Cytogenetic characterization and evaluation of c-MYC gene amplification in PG100, a new Brazilian gastric cancer cell line

Gastric cancer is the fourth most frequent type of cancer and the second cause of cancer mortality worldwide. The genetic alterations described so far for gastric carcinomas include amplifications and mutations of the c-ERBB2, KRAS, MET, TP53, and c-MYC genes. Chromosomal instability described for gastric cancer includes gains and losses of whole chromosomes or parts of them and these events might lead to oncogene overexpression, showing the need for a better understanding of the cytogenetic aspects of this neoplasia. Very few gastric carcinoma cell lines have been isolated. The establishment and characterization of the biological properties of gastric cancer cell lines is a powerful tool to gather information about the evolution of this malignancy, and also to test new therapeutic approaches. The present study characterized cytogenetically PG-100, the first commercially available gastric cancer cell line derived from a Brazilian patient who had a gastric adenocarcinoma, using GTG banding and fluorescent in situ hybridization to determine MYC amplification. Twenty metaphases were karyotyped; 19 (95%) of them presented chromosome 8 trisomy, where the MYC gene is located, and 17 (85%) presented a deletion in the 17p region, where the TP53 is located. These are common findings for gastric carcinomas, validating PG100 as an experimental model for this neoplasia. Eighty-six percent of 200 cells analyzed by fluorescent in situ hybridization presented MYC overexpression. Less frequent findings, such as 5p deletions and trisomy 16, open new perspectives for the study of this tumor.

Impact of HPV infection on the development of head and neck cancer

Human papillomavirus (HPV)-related head and neck squamous cell carcinoma (HNSCC) is considered to be a distinct clinical entity with better prognosis than the classical tobacco- and alcohol-associated tumors. The increasing incidence of this neoplasia during the last decades highlights the need to better understand the role of HPV in the development of these cancers. Although the proportion of HNSCC attributed to HPV varies considerably according to anatomical site, overall approximately 25% of all HNSCC are HPV-DNA positive, and HPV-16 is by far the most prevalent type. In this review we discuss the existing evidence for a causal association between HPV infection and HNSCC at diverse anatomical head and neck subsites.

Human papillomavirus infection among sexual partners attending a Sexually Transmitted Disease Clinic in Rio de Janeiro, Brazil

Cervical cancer is a major source of illness and death among women worldwide and genital infection with oncogenic human papillomavirus (HPV) its principal cause. There is evidence of the influence of the male factor in the development of cervical neoplasia. Nevertheless, the pathogenic processes of HPV in men are still poorly understood. It has been observed that different HPV types can be found among couples. The objective of the present study was to investigate HPV infections in female patients (n = 60 females/group) as well as in their sexual partners and to identify the concordance of HPV genotypes among them. By using the polymerase chain reaction, we detected a 95% prevalence of HPV DNA in women with cervical intraepithelial neoplasia (CIN) compared to 18.3% in women with normal cervical epithelium, with a statistically significant difference (P < 0.001). The HPV DNA prevalence was 50% in male partners of women with CIN and 16.6% in partners of healthy women. In the control group (healthy women), only 9 couples were simultaneously infected with HPV, and only 22.2% of them had the same virus type, showing a weak agreement rate (kappa index = 0.2). Finally, we observed that HPV DNA was present in both partners in 30 couples if the women had CIN, and among them, 53.3% shared the same HPV type, showing moderate agreement, with a kappa index of 0.5. This finding supports the idea of circulation and recirculation of HPV among couples, perpetuating HPV in the sexually active population, rather than true recurrences of latent infections.

Carcinoma de células renais com metástase cutânea: relato de caso

O adenocarcinoma do rim, ou hipernefroma, é a terceira neoplasia mais comum do trato geniturinário, sendo o de células claras o tipo principal, representando 60% dos casos, com pico de incidência entre 50 e 70 anos. A presença de metástase ao diagnóstico acomete em torno de 30% dos pacientes, tendo como principais sítios pulmões, ossos, pele, fígado e cérebro. Relatamos o caso de um paciente portador de carcinoma de células renais com metástase ao diagnóstico que, apesar de inserido na faixa etária predominante, tipo histológico mais frequente e quadro clínico característico, apresentava metástase a distância em local pouco observado na prática clínica. O paciente evoluiu para o óbito sem tempo hábil para o tratamento.

Nefroma mesoblástico congênito subtipo celular: relato de caso

INTRODUÇÃO: Nefroma Mesoblástico Con-gênito é uma rara neoplasia renal pediátrica. Apresenta dois subtipos histológicos, clássico e celular, sendo o último de pior prognóstico e responsável por aproximadamente dois terços dos casos. Esse tumor ainda é um desafio diagnóstico aos patologistas devido à similaridade com outras neoplasias pediátricas renais mais frequentes. RELATO DO CASO: Criança do gênero feminino, 2 anos e 9 meses de idade, foi encaminhada a serviço médico com referência em oncologia apresentando massa renal à esquerda. Após nefrectomia, o estudo do espécime mostrou, macroscopicamente, extensa área tumoral granular, brancoacinzentada, ocupando aproximadamente todo o rim, invadindo seio renal, cápsula e gordura perirrenal, com áreas de hemorragia e necrose. Histologicamente, caracterizava-se pela presença de células fusiformes e mitoses, sem atipias celulares. O diagnóstico foi de Nefroma Mesoblástico Congênito subtipo celular e a paciente foi submetida a quimioterapia. Durante o primeiro ano de tratamento, houve recidiva do tumor, apresentando-se irressecável e sem resposta a nova quimioterapia. A paciente foi a óbito aos 4 anos de idade. DISCUSSÃO: O subtipo celular do nefroma mesoblástico tende a ser mais agressivo, apresentando uma taxa de sobrevivência de 85%, comparada com 100% para a variante clássica. Geralmente, a recorrência ocorre no primeiro ano de tratamento, principalmente quando o subtipo é o celular.